Elevator safety appliance.



ELEVATOR SAFETY APPLIANCE.

APPLICATION FILED MAR. 5, 1907.

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SAMUEL BRUCE, OF HELVETIA, PENNSYLVANIA.

ELEVATOR SAFETY APPLIANCE.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed March 5. 1907. Serial No. 360,689.

To all whom it may concern:

Be it known that I, SAMUEL BRUCE, a citizen of the United States,residing at Helvetie, in the county of Clearfield and State ofPennsylvania, have invented new and useful Improvements in ElevatorSafety Applianoes, of which the following is a specificatlon.

The invention relates generally to an improvement in elevators, andparticularly to a safety appliance therefor adapted to automaticallylock the elevator cage or platform against movement in a downwarddirection in the event of breakage of the supporting cable.

The main object of the resent invention is the provision of safetyliivers operatively connected to the supportin cable and normallymaintained by the ifting strain on said cable in inoperative ornon-engaging position, the construction including an automaticallyoperable element serving, upon the breakage of the supporting cable, toproject the safety levers into locking engagement with the elevatorslides, and thereby lock the elevator against further movement in adownward direction.

The invention will be described in the following specification,reference being bad particularly to the accompanying drawings, in

which Figure 1 is a perspective view illustrating the application of myimproved safety a pliance, Fig. 2 is a view in elevation part y insection of the same, the safety levers being illustrated in looking orelevator supporting positions, Fig. 3 is a perspective view of one ofthe safety levers, Fig. 4 is a partial perspective of a slightlymodified form of safety lever.

Referring particularly to the drawings, the elevator structure withwhich my improvement is designed to cooperate may, for the purposes'ofthe present invention, be said to comprise frame timbers 1 disposed inspaced relation in the well, and carrying on their inner or proximatesurfaces the slides 2 on which the elevator is guided in movement. Theelevator cage or car' comprises a platform 3 secured to uprights 4designed to bear against the respective slides, said uprights beingconnected at their upper ends by a Guide plates are preferably secured.to the sides of the uprights to overlie and bear against the slides 2to insure the proper travel of the elevator during operation. The car iselevated and lowered through the medium of an operating cable 7,terminally secured to a clevis 8, which in turn is connected to the carthrough the medium of elevator chains 9, the car engaging ends of whichare preferably connected to the cross beam adjacent the respective endsof the latter.

The detailed structure described is intended to illustrate any desiredform of elevator and operating-parts therefor, as such structure formsno material part of the present invention and may, therefore, be changedor varied in any desired manner.

The present invention is directed primarily to a safety appliance, inthe use of which the car will be automatically locked against furtherdescent in the event of breaking of the supporting cable 7.

In detailed structure the safety appliance of the present inventionincludes a s ring frame 10, comprising an approximate y U- shaped stripof metal of appropriate strength, the terminals of the arms of which aresecured to opposing surfaces of the cross beam at points about centrallyof the length of the latter. The spring frame is of such size that inthis position the cross bar 11 thereof is arranged some distance belowthe lower surface of the cross beam and extends transverse the lengththereof, as clearly shown in Fl 1. i

ll draw-bar 12 is mounted for free sliding movement in a slotted opening13 formed in the cross beam, the upper edge of the bar be- .ing formedwith an upwardly (projecting ear 14 for the reception of one en of thebridle chain 15, the o posite end of which is connected to the c evis 8.The lower edge of the draw-bar is formed with a depending ear 16 towhich is connected one end of a tension member, referably a coil spring17, the o posite end of which is connected to a tie bo t 18 adapted tobe loosely passed through an opening in the cross bar 11 of the springframe, and terminally threaded to receive ad justing nut-19 and a locknut 20 beyond said cross bar 11.

Safety levers 21 are pivotally connected to opposing points of thedraw-bar, each of said levers comprising a suitable length of materialpreferably gradually reduced in transverse dimension toward the freeend. The relatively inner or connected end of each lever is preferablyslotted to provide spaced ears 22 adapted to embrace the edge of thetions.

draw-bar to insure a more substantial connection. The free ends of thelevers are reduced to a comparatively thin edge and formed with a seriesof teeth 23, said levers adjacent their free ends being slightlydefiected from the normal plane of the lever to provide an engagingportion 24.

The uprights 4 of the car structure are formed at appropriate pointswith slots 25, preferably inclining downwardly toward and alined withthe respective slides 2. In vertical dimensions the slots 25 aresomewhat larger than the engaging ends 24 of the levers, the inclinationof the upper wall of the slots corresponding to the inclination of theupper surfaces of the engaging ends 24, for a purpose which willpresently appear.

In assembling the safety appliance for use, with the parts constructedand arranged as described, the bridle chain 15 is so adjusted as toelevate the draw-bar to normally maintain the free or tooth ends of thesafety levers out of engagement with the slides 2. Through the medium ofthe nuts 19 and 20 the tie bolt 18 is then adjusted so as to put thespring 17 under the desired tension. With the parts thus arranged, thecar is free to be elevated or lowered in the usual manner, and in theevent of breakage or other rupture of the cable 7 the spring 17instantly operates to draw downward the draw-bar 12, and thereby projectthe free ends of the levers into engagement with the slides 2. As thepivot ends of the levers are supported some distance above the slots 25,it is obvious that the engaging portions 24 of the levers will, in thenormal positions of the parts, rest upon the lower wall of the slots 25,and as the spring operates said levers to force them into engagementwith the slides a comparatively free movement will be permitted. saidengaging ends 24 enabling them to effectively seat themselves inengaging posi- As the downward movement of the car continues and theupper walls of the slots engage the free ends of the lever, theinclination of said walls corresponding to the in clination of theengaging lever ends will more firmly seat said levers in slide engagingposition. The car is thus effectively locked against further deseentandmay be conveniently unlocked by simply elevating the car through anydesired connection.

In Fig. 4 is illustrated a slightly modified form of lever engaging end,whereby the cooperating teeth 26 are arranged in spaced rows extendingtransverse the length of the lever. This particular form is designed foruse with heavy cars or with cars adapted to support extreme loads, asthe double row of teeth will afford a more certain operation and preventdisengagement through the breakage of the teeth of one row. In both thepreferred. and modified form the engaging ends of the levers may, ifdesired, be treated to render them exceedingly hard, whereby they areadapted for engagement with metal slides as well as wooden slides.

While preferring the details of structure herein described and shown itis obvious that various changes and modifications may be resorted towithout materially affecting the function or purpose of the invention,and I wish it to be understood that I consider as within the spirit ofthe present invention all such changes and variations as may fall within the scope of the appended claims.

Having thus described the invention what is claimed as new, is:

1. The combination with an elevator car including a cross beam providedwith an. opening, of a U-shaped. frame secured to the cross beam, a drawbar slidably mounted in the opening of the cross beam, an elevatingcable secured to the draw bar, safety levers pivotally secured to saiddraw bar, a tie bolt adjustably secured to the cross bar of the U-shaped frame, and a spring secured at one end to the draw bar and at itsother end to the tie bolt.

2. The combination with an elevator car including a cross beam providedwith an opening, of a U-shaped frame having the terminals of its armssecured to opposite sides of the cross beam, a draw bar slidably mountedin the opening of the cross beam and between the arms of the U-sh apedframe, an elevating cable secured to the draw bar, safety leverspivotally secured to said draw bar, a tie bolt adjustably secured to thecross bar of the U- shaped frame, and a spring secured at one end to thetie bolt.

In testimony whereof, I allix my signature in presence of two witnesses.

SAMUEL BRUCE. Witnesses:

D. IN. GOULD, JOHN L. FLETCHER.

